Steganography and Piracy in the Age of Digital Distribution

Steganography Presentation

It’s clear that now more than ever content is getting distributed digitally. For example, Amazon recently revealed that it sold more books on the Kindle last quarter than hardcovers. Unfortunately for the copyright holders, digital content is super easy to pirate. And although the ethics of the situation are unclear (as a society, do we even want to enforce copyright?) this post proceeds from a frame that we have a digital property and want to protect it.

DRM (“digital rights management”) is out. People hate it (although the closed iTunes ecosystem might suggest otherwise, they might be an exception due to the dominance of Apple’s delivery infrastructure). In general, people want their files to be unencrypted so they can use them how they want and when they want. So how do you distribute your written content in a way that deters piracy? One method is to have your ebook distributor automatically add a stamp to every copy of your PDF. This is really easy to do, with only a few lines of code. Unfortunately, it’s also really easy to subvert, with only a few lines of code required to paste a big black block over every stamp.

A "secure" (unencrypted) PDF

You could password protect the file, instead, but the password can easily be distributed. The problem (from an abstract perspective) is that while you can do a unique one-way password decrypt, once you get into the content, you have access to all the information. Then you can redistribute the information however you want. What you need to do is somehow encode the information so that you have a way of identifying a unique signature, but at the same time not significantly visually shift the information in any way as to alert the viewer! In other words, the text itself (or the information-content itself) must be structured in a way that you can infer extra information.

My first proposed solution? Modifying the kerning of the text in a way that will subtly, yet uniquely, determine a key. The problem with my solution is that the text can be scanned and normalized, and then re-outputted as either a separate PDF or even a text file. The normalization process is difficult- by having to parse the PDF text, you’re forced to use some sort of OCR technology. This obstacle can be solved if you have a sufficiently randomized font, such that the person decrypting is forced to rewrite the OCR algorithm each time a new text is to be interpreted. This is a decent deterrent, but not foolproof.

Another solution: Make sure that the aesthetics of the presentation of the information are a significant value-add. That way, by normalizing the text, you’re losing information.

Another solution: embed some useful diagrams in your document, and use a steganography technique like LSB encoding to hide the user’s key. Unfortunately, it’s also easy for a would-be pirate to write software that applies a random pixel distribution wash over the entire page, in order to distort the obscured information.

So for god’s sakes, play your cards close to your chest and don’t let people know what’s up. But I’m working on some software to automatically add these sort of subtly protections to ebooks without disrupting the user’s ability to fully own and enjoy their purchase. Contact me if interested.



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  • Guest

    I really can’t see artificial limitations on infinite goods working particularly well no matter how clever you are about it.
    How about putting more effort in creating reasons for people to want to buy instead?

  • Guest

    I really can't see artificial limitations on infinite goods working particularly well no matter how clever you are about it.
    How about putting more effort in creating reasons for people to want to buy instead?

  • Stanley Moon

    My take on this is that eBooks should cost, say, $1 thereby negating any reason to rip them off. When and if we ever have a viable system of making micro-payments (why hasn’t Mondex taken off, for example?) this will transform the fortunes of authors. I very rarely shell out for books myself, partly because of the price and partly because of the sheer effort of doing it. Give me a USB Mondex card reader so that I know I can’t be ripped off for more than the card contents and charge me a dollar for a book and I’ll buy it without hesitating.

  • http://www.zacharyburt.com/ Zachary Burt

    My question to you is whether people are as price-sensitive as you think they are. If a book costs $20 on Amazon, in order to justify reducing its price to $1, it must then sell 20x more copies. Data from iTunes App Store merchants (e.g. as other sellers of digital wares) suggests that people are not always as price sensitive as you might think.

    On the other hand, I will readily buy songs for $.99 because it’s easier to do so with a single click than to go to the trouble of pirating them. I don’t know any absolute numbers off-hand but my intuition and recall suggests that music industry profits have absolutely declined.

  • Stanley Moon

    Zac, very glad to have discovered your blog.

    In answer to your point, I imagine that drastically reducing prices of ePublications *would* result in 20x more sales. The ‘traditional’ high price of books is set as much by the physical costs of printing, binding and transportation as much as anything else, isn’t it? (The same goes for the traditional costs of music distribution).

    Just thinking about this, I find myself buying fewer and fewer books these days. It’s something to do with the price, as I mentioned before, and the effort required to do it, but also that the internet has changed my perception of books as being ‘dead’. That is, unless I physically go to a shop I have to wait for them to be delivered, they are immediately out of date (like printed newspapers) and they offer little chance for me to interact with the author (unlike your esteemed blog).

    I haven’t bought a CD for years, but I *do* pay a monthly fee for unlimited music streaming. Again, I have lost the desire to physically ‘possess’ the material; I am perfectly happy with the internet version which also gives me immediate access to the musicians’ web sites, other users’ recommendations etc. (I do have a slight gripe about the audio compression). The $0.99 you pay for a track doesn’t seem low enough to eliminate piracy, it seems to me, and is pretty much the ‘traditional’ cost of a track on a CD..?

  • Stanley Moon

    My take on this is that eBooks should cost, say, $1 thereby negating any reason to rip them off. When and if we ever have a viable system of making micro-payments (why hasn't Mondex taken off, for example?) this will transform the fortunes of authors. I very rarely shell out for books myself, partly because of the price and partly because of the sheer effort of doing it. Give me a USB Mondex card reader so that I know I can't be ripped off for more than the card contents and charge me a dollar for a book and I'll buy it without hesitating.

  • http://www.zacharyburt.com/ Zachary Burt

    My question to you is whether people are as price-sensitive as you think they are. If a book costs $20 on Amazon, in order to justify reducing its price to $1, it must then sell 20x more copies. Data from iTunes App Store merchants (e.g. as other sellers of digital wares) suggests that people are not always as price sensitive as you might think.

    On the other hand, I will readily buy songs for $.99 because it's easier to do so with a single click than to go to the trouble of pirating them. I don't know any absolute numbers off-hand but my intuition and recall suggests that music industry profits have absolutely declined.

  • Stanley Moon

    Zac, very glad to have discovered your blog.

    In answer to your point, I imagine that drastically reducing prices of ePublications *would* result in 20x more sales. The 'traditional' high price of books is set as much by the physical costs of printing, binding and transportation as much as anything else, isn't it? (The same goes for the traditional costs of music distribution).

    Just thinking about this, I find myself buying fewer and fewer books these days. It's something to do with the price, as I mentioned before, and the effort required to do it, but also that the internet has changed my perception of books as being 'dead'. That is, unless I physically go to a shop I have to wait for them to be delivered, they are immediately out of date (like printed newspapers) and they offer little chance for me to interact with the author (unlike your esteemed blog).

    I haven't bought a CD for years, but I *do* pay a monthly fee for unlimited music streaming. Again, I have lost the desire to physically 'possess' the material; I am perfectly happy with the internet version which also gives me immediate access to the musicians' web sites, other users' recommendations etc. (I do have a slight gripe about the audio compression). The $0.99 you pay for a track doesn't seem low enough to eliminate piracy, it seems to me, and is pretty much the 'traditional' cost of a track on a CD..?

  • http://twitter.com/AlexGraul Alex Graul

    Or you could just set the password to something people aren’t going to want to distribute like their email or CC number.

  • http://twitter.com/AlexGraul Alex Graul

    Or you could just set the password to something people aren't going to want to distribute like their email or CC number.

  • Anonymous

    On the model of EndAnts, what about a site like that for understanding games? I guess the automated structure you proposed is very cool, except maybe for the for the last step (7).

    I am enjoying your work pretty much. The awesomenessreminders is pure genius btw

  • soro

    On the model of EndAnts, what about a site like that for understanding games? I guess the automated structure you proposed is very cool, except maybe for the for the last step (7).

    I am enjoying your work pretty much. The awesomenessreminders is pure genius btw

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